Environments whose purpose is to entertain, educate or otherwise hold the attention of its participants risk becoming boring when each response is tied to a single input stimulus and the result is invariably the same. In such a system the amount of interaction is low and the result highly predictable. Presently, this is the condition of so-called interactive playgrounds. Present interactive playgrounds respond in the same way to a stimulus without significant variation over time. As these environments become predictable to the participants they correspondingly run the risk of becoming boring to those participants. Eventually, bored participants will choose to avoid such an environment. Thus, whether or not a particular environment becomes boring will often have economic and other consequences for the owners of such an environment. The degree of interaction and the predictability of the environment's response are two important factors in determining whether an environment becomes boring or not.
Presently, interactive playground environments utilize strict rule based systems to control their response. A strict rule based system always responds to stimuli according to one rule. The control is of a top-down type variety in the sense that there is a static set of rules that mediates the output response in a deterministic way.
FIG. 1 illustrates such a rule based system. In FIG. 1, outputs from sensors 10 are transmitted to a computer executing a set of rules 12. The set of rules 12 determine what response 14 is appropriate based on the sensor output 10. The set of rules 12 does not change.
In FIG. 2 the set of rules block 12 in FIG. 1 is expanded to show typical functional sub-systems within the rules block 12 to better illustrate the strict rule based system. The sequential nature of a strictly rule based system requires a perception unit 16 to process information from the sensors 10. The system 12 then updates its current information from the environment in the mapping unit 18. A planning unit 20 and an execution unit 22 then derive and transmit the response 14. These units individually do not have the ability to respond as a system, nor is every unit capable of creating any type of observable behavior in the output. Thus, the strictly rule based system takes an input and operates on that input to produce a result. For the same input, the same result is produced every time. This is often referred to in the art as "hit and run" animation. The designer of this type of system assumes a static problem domain, i.e. the response is static. Ultimately, participants in the strict rule based interactive playground discover the playground is too predictable, then those participants lose interest and avoid it.
In order to keep the participants' attention and reduce the risk of boredom, it would be desirable to have an interactive playground that is less predictable. Furthermore, it would be desirable for an interactive playground to promote higher levels of interaction with its participants.